What is the difference between NANC transmitter and co-transmitter?

I was just wondering, what is the difference between non-adrenergic non-cholinergic (NANC) transmitter and co-transmitter in the synaptic communication between neurons? In particular, what are their different functions?

I was just wondering, what is the difference between non-adrenergic non-cholinergic (NANC) transmitter and co-transmitter in the synaptic communication between neurons? In particular, what are their different functions?

Many thanks,
Jay

Co-transmitters are thought to have a modulating function on the neuron-specific transmitter. In some cases the co-transmitter only is released with low-frequency signaling. With higher frequency signaling the main transmitter is also released. I'm not sure why you exclude cholinergic and adrenergic neurons, but in dopaminergic neurons, glutamate has been observed as a co-transmitter. The actions of dopaminergic neurons terminating in the nucleus accumbens (NAc) are described in the linked article (see conclusion).